The invention comprises a hand tool in the general configuration of pliers having gripping jaws or cutting edges. The invention can be used for gripping, clamping, or cutting objects. A critical feature of the tool is the use of force multipliers to transfer force from a hand lever to a gear reduction hub that is connected to one of the jaws. Force multipliers are devices that are able to provide greater output force than input force. Examples of force multipliers include levers, pulleys, screws, gears, and hydraulic pistons that are configured to increase output force.
For example, the preferred embodiment of the tool is a ratcheting cutter has force multipliers working together to produce sufficient torque to cut through any metal, including titanium. This kind of tool can readily be configured such that 52 lb-ft of torque at the handle will produce over 100,000 lb-ft of torque at the cutting head in a smooth and continuous progression of applied force. This cutting device can be used in a variety of fields, but is particularly suited for use as a ring cutter. In addition, such a tool can cut through fencing, pad locks, cable, and bolts. With a different head design, the tool can be used for gripping and clamping onto various surfaces.
The preferred embodiment of the tool is configured in the general form of a hand tool having a pair of handles of which the lower handle acts as a lever, being joined to a double fulcrum force multiplier that is connected to an engagement pawl. By applying force to the lower lever it substantially increases the force applied to a pawl, which in turn rotates a gear hub which acts as another force multiplier. By pushing a detentable button at top of tool, a slide will move down the back of cam release slide and cause a locking pawl to engage the hub. When the locking pawl is engaged, a spring in the pawl ejects the pawl from gears and allows the gear hub to rotate forward in a ratcheting manner as the handles are repeated squeezed together and released. This causes the upper jaw at the opposing end to advance towards the lower jaw in a controlled manner for clamping or cutting. When finished, the user may push the detentable button on the top of the tool to a different position, thus causing the slide to disengage the locking pawl from the gear hub, thus allowing the tool to return to a reset position.
The tool can also be made using other combinations of force multipliers to apply force to a gear reduction hub. For example, in another embodiment, the lower handle can be squeezed to drive a bar having a pawl at its end into the teeth of gear which in turn drives the gear reduction hub to rotate in a forward direction.